Need Help - Override tcp session timeout due to Source_addr Persistence

The way this would be used in the scenario it sounds like you're outlining, is that you would create seperate pools for your "preferred" and "fallback" hosts.

You would then configure your VIP to send traffic to the "preferred" pool, with no fallback host setup.

Then, you'd put this rule in place, like you listed above:

rule nopersist_failover {
  when LB_FAILED {
    persist none
    LB::reselect pool fallback_pool
  }
}

What this does is makes it so that if your preferred pool is ever unavailable, the iRule will route requests to your fallback pool, but only after disabling persistence. This means that as soon as the preferred pool is back online, requests will automatically be sent there again.

HTH,

-Colin